Topic: Energy and Environment

New Evidence that Plants Are Slowing the Growth of Greenhouse Gases

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”

Scientists have known for decades that, as global carbon dioxide levels increase, so too does the standing biomass of the world’s plants. Carbon dioxide is a strong plant fertilizer.

As plants grow better, they also increasingly act as carbon sinks as they convert atmospheric carbon dioxide, with a little help from water and sunshine, into carbohydrates stored as biomass. Some of that carbon is returned to the air annually through decomposition, but other portions are are stored for longer periods in the soil, downed logs, houses, etc.  This plant-based carbon sink helps to offset the growth of global carbon dioxide emissions from human activities (primarily from the burning of fossil fuels). Together, the terrestrial carbon sink, along with the oceanic carbon sink, annually takes up more than half of the anthropogenic CO2 emissions—and remarkably, as global CO2 emissions have increased, so too has the global CO2 sink.

But now comes new evidence that plants may be helping to combat global warming through another mechanism as well, slowing the build-up of the atmospheric concentration of methane (a greenhouse gas some 25 times more effective than CO2 on a molecule-for-molecule bases at adding pressure for the world to warm).

As shown in the fugure below the jump, the growth rate of the atmospheric concentration of methane (CH4)—which is projected by the IPCC to be rising rapidly—began slowing down in the early 1990s and even topped out for a few years in the mid-2000s. Since about 2007, the atmospheric concentration of CH4 has been rising again, but only at about half that of the pre-1990 rate.

Figure 1. Atmospheric methane concentration (source: National Oceanic and Atmospheric Administration).
This behavior is not understood by climate scientists. It contravenes alarmist scenarios of runaway global warming fueled by a positive methane feedback (the scenario for which is that warming leads to thawing of the arctic permafrost, which releases methane, which leads to more warming, and so on).

A team of scientists from Lund University and Stockholm University set out to investigate recent claims that some plants release methane and are therefore a source of global methane emissions. They set up instruments to measure methane exchange on a collection of individual branches of four different tree species in a 100-year-old forest in central Sweden. A set of control experiments was also conducted in a laboratory setting. They just published their findings in the journal Geophysical Research Letters. Much to their surprise, the researchers found that the trees (both in the field and in the lab) were taking up methane rather than releasing it. They suggest that the presence of a “bacteria with the ability to consume [methane] would be a possible explanation for [the observed behavior].”

That’s not the only good news.

The researchers then executed the extremely risky (and oft ill-advised) maneuver of scaling up from a few tree branches in central Sweden to the level of the global forest canopy. Their research “indicates that the canopy might play an equally important role [in CH4 uptake] as the soil in the global context.” In other words, their results show that trees are playing a large (and hitherto unknown) role as a sink in the global methane cycle.

The culprit?  Increasing atmospheric carbon dioxide.

In the authors’ own words (with my emphasis):

Two recent studies give alternative explanations to the slow-down in the growth rate of atmospheric methane in the last decades. One of them indicates that it is due to a stabilization of fossil-fuel emissions (Aydin et al., 2011) whereas the other explains it by a decrease in microbial methane sources in the northern hemisphere (Kai et al., 2011). Our results offer a third explanation: that an increasing amount of CH4 has been taken up by vegetation during the last decades as a consequence of increased greenness (Myneni et al., 1997), NPP [net primary production] (Nemani et al., 2003) and GPP [gross primary production] (Chen et al., 2006) as observed by satellite remote sensing.

This is still highly a highly speculative result and one that will require a heck of a lot more study and independent confirmation. But it is a novel finding and goes to show that there is still a lot of interesting research ongoing in the field of climate (change), and that most definitely the science is not “settled.”


Reference:

Sundqvist, E., et al., 2012. Atmospheric methane removal by boreal plants. Geophysical Research Letters, 39, L21806, doi:10.1029/2012GL053592

Did Global Warming Reduce the Impacts of Sandy?

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”

The press has been quick to jump on the idea that post-tropical cyclone Sandy (it was not a hurricane at landfall) was worsened by anthropogenic global warming and that “superstorms” are here to stay.

But I must ask the impertinent question: could anthropogenic global warming actually have lessened the impacts of Sandy?

There are basically three pro-global warming talking points involving Sandy: 1) global warming has caused sea levels to rise, thus making the storm surge larger, 2) global warming has led to higher sea surface temperatures and thus stronger hurricanes, and 3) global warming is making extratropical circulation features more conducive to intense and slower moving storm systems.

There is precious little evidence to definitively support any of these points when applied to Sandy, and, in fact, there exists a body of evidence pointing to the opposite conclusion—that anthropogenic global warming may have actually acted to mitigate the intensity of Sandy. Perhaps what lies closest to our current best understanding is that anthropogenic global warming made little contribution one way or the other.

Let’s start with sea level rise.  Water levels at New York City’s Battery Park location have been measured and recorded since 1856. The full record shows an overall (relatively steady) rise of about 0.11 inches per year, for a total rise between 1856 and now of just a bit more than 17 inches. How much of this has to do with anthropogenic global warming? Maybe a third, or about 6 inches. Of the rest, about half was caused by a subsidence of the land (geological processes related to the end of the last ice age, see Engelhart et al., 2009 for example), and the remainder to a warming up from the naturally occurring cold period which ended in the mid-19th century. So of the total 17.34 feet of water (above the station datum) recorded at The Battery tide gauge during the height of Sandy, about 0.5 feet of that could probably be linked to anthropogenic global warming.  This is not nothing, but the overwhelming majority of the damage done by the storm surge would have happened anyway. For comparison, the influence of the full moon that night was about as large as the influence of anthropogenic global warming.

As to anthropogenic global warming’s impact on the path, frequency, and intensity of hurricanes, there is a mixed bag of potential outcomes which may be detectable far in the future (towards the end of the century)  if anthropogenic greenhouse gas emissions continue to rise. The current science suggests that the frequency of hurricanes could decrease, the intensity may increase slightly, and the preferred path may be displaced out to sea (Wang et al., 2010). The net effect on the U.S. is anyone’s guess at this point (but 2 of the 3 argue for fewer hurricane impacts in the U.S.).  But what virtually everyone does agree upon is that any influence of anthropogenic global warming on hurricane characteristics is not detectable in today’s climate (see for example, Knutson et al., 2010). So that talking point is basically off the table.

Which brings us to the third global-warming-made-Sandy-worse talking point—the influence of anthropogenic global warming on the extratropical circulation characteristics.

This is where the rubber really meets the road when it comes to Sandy’s behavior.  Without the northward, and ultimately westward pull from the upper atmospheric jet stream, Sandy would have progressed harmlessly eastward, away from the Northeast coast, and out to sea.  But that is not what happened. Instead, a fairly deep trough (southward excursion) of the jet stream was coincidentally passing through the eastern U.S. just as hurricane Sandy was progressing up (but offshore) the U.S. Eastern Seaboard. This trough had the effect of attracting Sandy, and drawing it northwestward, pumping energy into it, and changing its character from a hurricane to an extra/post tropical storm system (also known as a Nor’easter in this part of the country).  In October, this type of behavior is not particularly unusual. The preferred tropical cyclone track maps provided by the National Hurricane Center (Figure 1) indicate a general tendency for tropical cyclones in October to curve back into the northeastern U.S.—just like Sandy did.

Figure 1. Prevailing tropical cyclone tracks for the month of October (source: National Hurricane Center, http://www.nhc.noaa.gov/climo/)

In fact, since the beginning of the 20th century, there have been about a dozen or so tropical cyclones that have made landfall in the U.S. north of Cape Hatteras which had a westerly component to their trajectory either immediately before or just after they came ashore. This includes historically damaging storms such as the 1903 New Jersey hurricane, the 1938 Long Island Express hurricane, and 1972’s Hurricane Agnes which is still the flood of record in many parts of the Northeast.

The last one was tropical storm Danielle, over twenty years ago. This is the longest interval in the record (since 1900) between westward-component storms north of Hatteras.  So much for the influence of global warming!

So, given this fairly typical behavior—why would anyone even consider that anthropogenic global warming played a role in Sandy?

For two reasons: 1) any bad weather these days is immediately linked to global warming by someone with an agenda, and 2) there was a paper published last spring (Francis and Vavrus, 2012) in which the authors concluded that the decline of Arctic sea ice (tied to anthropogenic global warming) was causing the Arctic to warm up faster than the lower latitudes, reducing the natural north-south temperature gradient which is where the jet stream (and extratropical storms) gain energy.  According to Francis and Vavrus, a less energetic jet stream contracts and becomes more meandering, with relatively deeper troughs and higher ridges which produce slower moving storm systems and more extreme weather.

Since Sandy was strengthened and pulled ashore by a deep trough/ridge system in the jet stream, folks are quick to assume that the Francis and Vavrus mechanism tying in anthropogenic global warming must be involved.

Not so fast!

This is like claiming to have made a new discovery that, when flipping a coin, heads are now more likely to occur than tails.  And wouldn’t you know, the next time the coin is flipped, it came up heads—to which you proclaim, “See, I told you so.” And since heads are associated with a bad outcome, the press flock to your explanation.  But what is completely overlooked, is that other researchers have examined every coin flip for the past 60 years and found that heads and tails occur with equal likelihood. So the current heads outcome is simply part of the natural 50-50 occurrence of heads or tails.

In this case, the other researchers are a pair of atmospheric scientists from Cornell University which have examined the forward speed of all nor’easters along the East Coast from 1951 through 2006 (Bernhardt and DeGaetano, 2012). And what they found, in their own words, was “There was no clear trend in [nor’easter forward] speed during the time period, although considerable season-to-season variability was present.” In other words, while there is a lot of storm-to-storm and season-to-season variability, there is no overall trend towards slower moving nor’easters (Figure 2)—so much for the Francis and Vavrus hypothesis.

Figure 2. Average speed of East Coast winter storms (nor’easters), from 1951-2006 (source: Bernhardt and DeGaetano, 2012).

And, there has been a lot of other research on changes in the patterns and characteristics of the Northern Hemisphere jet stream during the period of anthropogenic global warming which did not find that same thing that Francis and Vavrus found (we detailed many of these findings in our March 8, 2012 Current Wisdom).  At least one of those papers suggested that the methodology employed by Francis and Vavrus “can generate false, or mask actual, variability patterns including trends” (Strong and Davis, 2007). Others concluded that global warming contracted, the jet stream, flattened it over the eastern U.S., and sped it up a bit—characteristics, which, along with a decreased temperature gradient, if applied to Sandy, would have combined to produce a less intense post tropical storm system than if global warming had not been occurring.

So rather than anthropogenic global warming making Sandy worse, it could have actually lessened its intensity and impacts.

The truth is, is that it is impossible to know how, or even if, global warming played any role at all in the lifecycle of Sandy. The science is all over the map, and the signal-to-noise ratio is so low that no matter what is occurring its impact in any direction is undetectable.

But it is sexier and has much more press appeal to proclaim that the destruction wrought by “superstorm” Sandy is the product of our unrestrained fossil fuel consumption, rather than the equally plausible opposite—that anthropogenic climate changes may have combined to lessen Sandy’s intensity.


References:

Bernhardt, J.E., and A.T. DeGaetano, 2012. Meteoro­logical factors affecting the speed of movement and related impacts of extratropical cyclones along the U.S. east coast. Natural Hazards, 61, 1463-1472, doi:10.1007/s11069-011-0078-0

Engelhart, S.E., et al., 2009. Spatial variability of late Holocene and 20th century sea-level rise along the Atlantic coast of the Unites States. Geology, 37, 1115-1118.

Francis, J., and S. Vavrus, 2012. Evidence linking arctic amplification to extreme weather in mid-latitudes. Geophysical Research Letters, 39, L06801, doi:10.1029/2012GL051000.

Knutson, T. R., et al., 2010. Tropical cyclones and climate change. Nature Geoscience, 3, 157-163, doi: 10.1038/ngeo779

Strong, C., and R. Davis, 2007. Winter jet stream trends over the Northern Hemisphere. Quarterly Journal of the Royal Meteorological Society, 133, 2109-2115, doi:10.1002/qj.171

Wang, C., et al., 2011: Impact of the Atlantic warm pool on United States landfalling hur­ricanes. Geophysical Research Letters, 38, L19702, doi:10.1029/2011GL049265.

Response to Federal Critics of our Report on Climate Change Impacts in the U.S.

The Cato Institute’s Center for the Study of Science has released the author’s proof version of its major report examining the potential impacts of climate change in the United States. It’s called Addendum: Global Climate Change Impacts in the United States (the final copy will be available shortly).

Our document grew from our desire to show how the government report upon which ours is based could have/should have looked if the original scientists involved had included a more thorough (less narrow) review of the scientific literature, and had not been obviously predisposed towards climate change doom and gloom.

Our report refers to itself as an “Addendum” to draw attention to the fact that the original 2009 report from the U.S. Global Climate Change Research Program (USGCRP) was incomplete, insufficient and badly in need of an update to include both scientific results published since its release and to include scientific research that was overlooked or ignored in that original document.

In general, our report, while pointing out that the earth’s temperature is rising and that human activities play a role, paints a more modest picture of climate change and its effects in the U.S. and emphasizes our adaptive capacity to handle a large amount of change in virtually all aspects of society. The overall tone of the Cato report is an optimistic one—a stark contrast to the pessimism that pervades the USGCRP report.

USGCRP Authors React

Our report has drawn ire from climate change alarmists, as well as from a subset of the group of scientists which authored the original USGCRP report.  We note that those who signed the group note make up barely a third of the 31 scientists who authored the USGCRP report. Eleven USGCRP co-authors released a statement airing their discontent in which they said:

As authors of [the USGCRP] report, we are dismayed that the report of the Cato Institute, ADDENDUM: Global Climate Change Impacts in the United States, expropriates the title and style of our report in such a deceptive and misleading way. The Cato report is in no way an addendum to our 2009 report. It is not an update, explanation, or supplement by the authors of the original report. Rather, it is a completely separate document lacking rigorous scientific analysis and review.

In fact, one of the primary ways that our report intended to make its point was by mimicking the style of the USGCRP report (in this case, imitation is not a form of flattery).  It is what the government report would have looked like had the authors been more open-minded and inclusive of the scientific literature.  In places where it was determined the original authors had done an adequate job, those sections were included verbatim, which we were certainly explicit about! This was all clearly explained in the “About this Report” section of our report (p. 8; analogous to their p. 7):

This Addendum is similar in format to the 2009 USGCRP report, allowing a facile reference for science that was omitted. In some places, we have moved text verbatim from the 2009 report to this Addendum.

That’s “deceptive or misleading?” The front cover of our report, smack in the middle of the page it says “Center for the Study of Science, Cato Institute.” That’s deceptive or misleading? The back cover is completely blank except for the prominent Cato Institute logo. There is a letter of introduction (p. 3 in both documents) written and signed by (then) Cato President Edward Crane. And “The Cato Institute” is included in the running header of every left-hand page in the document.

Deceptive or misleading? All of this led the world’s most prominent and popular climate blogger Anthony Watts to state “How anyone with even limited intelligence could get the idea that the report is from the US Government/NOAA is truly laughable, because if they can’t read “Cato Institute” clearly printed on the front and back cover, then they probably aren’t capable of reading and interpreting the original report either.”

As to the USGCRP co-authors statement that the Cato report is not “an addendum…an update, explanation, or supplement by the authors of the original report” this is certainly true. The original authors had nothing whatsoever to do with our report. In fact, the original authors substantively ignored virtually every comment in a 77-page single-spaced (24,958 word) review of their draft document that we submitted in August, 2008—which is why they are now seething over our Addendum, which is partially based on that review.   It is their very poor job, which is so misleading in spots that it appears intentional, that required a subsequent addendum, update, explanation, and supplement, or whatever you chose to call it.

And as to their claim that our report is “lacking rigorous scientific analysis and review,” any reader of our report will find the text to be well documented and derived primarily from the well-accepted material.  Our report describes its source material this way:

This Addendum is primarily based upon the peer-reviewed scientific literature, peer-screened professional presentations, and publicly-available climate data. We include literature through the beginning of 2012, which of course could not be in the 2009 [original USGCRP] report. But there are also a plethora of citations from 2008 or earlier that were not included in the US­GCRP document. Why that is the case is for others to determine.

These sources are no less rigorous (and certainly more inclusive) than those assessed/included by the original USGCRP authors.

The co-authors of the group letter go on to note four other points that they wish to emphasize.

Quality References

The first has to do with the number/quality of references included in the USGRCP report vs. our report. Both reports draw primarily from the peer-reviewed scientific literature. That our report includes a large number of peer-reviewed studies directly relevant to climate change impacts in the United States that were not included in the USGCRP report, and which support a more modest impact, in and of itself speaks volumes. Instead of quibbling over the number of references, the USGCRP co-authors ought to be apologizing profusely for producing such an incomplete and one-sided report on the taxpayers’ dime.

Effectiveness of Public Comment

Another bone of contention is that the USGCRP report was open to public comment while our report was not. But, as Ed Crane described in his introductory remarks in the report, the public comment process for the USGCRP report left a lot to be desired:

This effort grew out of the recognition that the original [USGCRP] document was lacking in scope and relevant scientific detail. A Cato review of a draft noted that it was among the worst summary documents on climate change ever written, and that literally every paragraph was missing critical information from the refereed scientific literature. While that review was extensive, the restricted timeframe for commentary necessarily limited any effort. The following document completes that effort.

And, of course, our Addendum is a public comment.  As is the letter signed by 11 of the USGCRP report’s original authors.

Modest Climate Change

Here is the third point made by the USGCRP author team:

The authors of the Cato Institute report agree with our Committee’s conclusions that global warming is unequivocal and consistent with a change in greenhouse gas effects attributable to human activities. They also conclude that climate change will continue to occur as greenhouse gas concentrations increase. However, their conclusions that future climate change will be benign, if not beneficial, and easily adapted to, diverge markedly from our Committee’s view regarding the seriousness of the risks. This is because the Cato Institute authors assume—based on their own analysis and contrary to peer-reviewed, contemporary science—that warming, intensification of weather extremes, polar ice cap melting, and sea-level rise will all be at the lowest end of the ranges projected in the Fourth Assessment of the Intergovernmental Panel of Climate Change.

I largely agree with all of this except the phrase “based on their own analysis and contrary to peer-reviewed, contemporary science”—in fact, our entire report is largely built upon the peer-reviewed, contemporary science.  And our “conclusions that future climate change will be benign, if not beneficial, and easily adapted to” are well-supported by the literature (and, as we point out, common sense). That the USGCRP co-authors find otherwise, or at least fail to even consider this very strong possibility, is the primary fault in their report that we address.

NAS Reports

The fourth and last point made by the USGCRP author team is that the USGCRP findings are backed by recent National Academy of Sciences reports. To me this is a hollow claim, as the NAS reports are about as selective in their science as the USGCRP report. Most of the NAS reports mentioned by the USGCRP authors in support of their report have been taken apart by the Cato Center for the Study of Science staff (see here and here, for example).

Future Update

And finally, the USGCRP co-authors note:

The next U.S. National Climate Assessment is underway under the auspices of the U.S. Global Change Research Program, with draft sections of its report to be released in December and completed in 2013. We are confident that this new assessment will reinforce and extend the findings of Global Climate Change Impacts in the United States.

Well that last line sure sounds like a bummer. My guess is that there will soon be another Addendum report from the Center for the Study of Science in the making.  In fact, the last substantive section of their document is titled “A vision for future U.S. assessments.”  Ours is titled “Future federal science assessments,” and says:

Future assessments of climate change are likely to be as poor in quality as Global Climate Change Impacts in the United States…However…each  new federal assessment is likely to be answered like the USGCRP report was—with more science than our federal government chooses to recognize.

Note: This is post is a substantial modification of one that originally appeared at MasterResource.org.

Global Science Report and The Current Wisdom Now on Cato@Liberty

Fans of Cato@Liberty may have noticed two new features from the Center for the Study of Science.  These are a weekly Global Science Report and a monthly Current Wisdom

While the Wisdom has been a monthly feature that can be found under my publications, World Science Report is new and is modelled after my original blog, Global Climate Report, which is the Web’s longest running climate change blog.  Our first release was September 11, 1995. The enormous archive at http://www.worldclimatereport.com is cross-referenced by subject and date, and can provide valuable information on virtually any climate question.  We also reserved the right to write in a humorous fashion.

As the Center adds new affiliates, you will see much more in the new World Science Report than mere climate.

Continuing to Lower the Sea Level Rise Contribution from Antarctica

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”

The good news keeps coming in about sea level rise—or more precisely, Antarctica’s (minimal) contribution to it. Last time, we reviewed recent scientific findings indicating Antarctica was on the verge of gaining ice mass (and thus acting to draw down global sea level) as a slightly warmer Southern Ocean results in increasing snow accumulation which acts to offset ice loss from its peripheral (marine-terminating) glaciers.  Without a contribution from Antarctica, alarming visions of a large and rapid sea level rise this century—upwards of a meter  (and by some reckoning up to 6 meters)—are pretty much out the door.  Sans Antarctica, we are looking at a foot to foot-and-a-half of rise, give or take a few inches. Such an amount will undoubtedly require some adjustment and adaptation, but will not involve a wrenching transformation of society. Most of us probably wouldn’t even notice. Consider that, due to a combination of geology and oceanic warming, this same amount (or more) has been experienced in many East Coast locations in the last 100 years.

The good science news may be one reason why global warming has been so absent in the election debates. In response,  last week, the Union of Concerned Scientists helped a collection of local government officials and scientists from Florida pen an open letter to the candidates imploring them to address the issue of sea level rise during their third and final debate (held in Boca Raton).  They didn’t.

It is a good thing that they left the issue alone, for in this week’s Nature magazine comes more evidence that Antarctica is perhaps not going to be the great sea level rise contributor that other research as made it out to be (e.g. Velicogna et al., 2009; Rignot et al., 2011).

Matt King, from Newcastle University, and colleagues set out to refine the Antarctic ice mass change calculations that have been performed using data collected by the Gravity Recovery and Climate Experiment (GRACE) satellite. GRACE determines how the mass is changing underneath the satellite by measuring temporal variations in the pull of gravity.  If the strength of the local gravitational attraction increases over time, then it is inferred that the local mass must be increasing (and vice versa).  This is a handy tool for assessing trends in dynamic ice/snow mass in places like Greenland and Antarctica.

But, variations in the ice/snow burden are not the only thing that can change the gravitational pull observed by the GRACE satellite. The ground underlying the ice and snow may be changing as well. And, in fact, it is. The ground in many places around the world is still adjusting to the burdening and subsequent unburdening from the coming and going of the massive amount of snow and ice from the last ice age (and its termination). This process is known as glacial isostatic adjustment (GIA).

The problem is that while we understand that GIA is taking place, we really don’t precisely know the details, like where, when, and how fast—especially over sparsely monitored and studied places like Antarctica.

Two  years ago, a study was published that showed that the GIA model used in most GRACE-based studies was in error, and that when it was corrected, the rate of calculated ice mass loss from across Antarctica declined by some 40 percent  (from ~150 gigatons/yr to ~87 Gt/yr). Since it takes about 374 Gt of melted ice to produce 1 millimeter of global sea level rise, these findings indicated that Antarctica was contributing to sea level rise at a rate of about one-quarter of a millimeter per year (or about 1 hundredth of an inch per year). We detailed that finding, by Xiaoping Wu and colleagues, in a Cato Current Wisdom article in October of 2010.

Now along comes the new study Matt King et al. (2012) that further refines the local GIA over Antarctica. Here is how they did it:

Here we applied a new GIA model (W12a) to GRACE data to estimate the ice-mass balance for 26 independent Antarctic drainage basins from August 2002 to December 2010. The W12a model comprises a glaciologically self-consistent ice history constrained to fit data that delimit past ice extent and elevation, and an Earth viscosity model chosen such that GIA predictions from W12a best fit a suite of relative sea-level records around Antarctica. The advance of W12a on previous models applied to GRACE data is illustrated by the misfit to GPS uplift rates being halved. Our use of W12a addresses the dominant GRACE-related error in previous Antarctic analyses.

With this new model in hand, they were able to produce a new estimate of the rate of ice mass change over Antarctica from 2002 through 2010. That estimate is a loss of only 69 Gt/yr (+/- 18Gt/yr). And further, they found no statistically significant change in this rate when averaged over the whole continent—in contrast to other prominent studies (e.g. Rignot et al., 2011) which claimed a significant acceleration was taking place.

So King and colleagues’ latest refinement puts the Antarctic contribution to global sea level rise at a rate of about one-fifth of a millimeter per year (or in English units, 0.71 inches per century).

Without a significantly large acceleration—and recall the King et al. found none—this is something that we can all live with for along time to come.


References:

King, M., et al., 2012. Lower satellite-gravimetry estimates of Antarctic sea-level contribution. Nature, doi:10.1038/nature, http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11621.html

Rignot, E., et al., 2011. Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise. Geophysical Research Letters, 38, L05503, http://www.agu.org/pubs/crossref/2011/2011GL046583.shtml

Velicogna, I., 2009. Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE. Geophysical Research Letters, 36, L19503, http://www.agu.org/pubs/crossref/2009/2009GL040222.shtml

Washington Post Sees Solar Panel Duties for What They Are: Self-Flagellation

The Washington Post was channeling the Cato Institute’s Herbert A. Stiefel Center for Trade Policy Studies in this morning’s succinct and insightful editorial about the foolishness of taxing imports of Chinese solar panels.

The editorial picks up a few of the themes and draws very similar policy conclusions to those we have been advocating for many years and, without stating it explicitly, presents a compelling case for major reform, if not repeal, of the trade remedies laws.

For context, last week the U.S. Commerce Department published the final rates of duty calculated in both antidumping and countervailing duty (anti-subsidy) investigations of imports of Chinese solar panels, which were initiated in October 2011. (Here are some earlier thoughts on the matter.)

Formal antidumping and countervailing duty orders will take effect, probably, next month following a final determination by the U.S. International Trade Commission that the U.S. solar panel industry has been materially injured by these Chinese imports.

The thrust of the editorial is that the antidumping and countervailing duties, which are “calculated” by Commerce using an absurdly inaccurate, punitive methodology, will hurt other U.S. companies that are downstream and upstream of the solar panel producers in the production supply chain.

Noting the transnational nature of solar panel production, the editorial states:

U.S. firms that export polysilicon, a key material in the panels’ manufacture, or machinery to Chinese solar-panel makers could lose – if not because of the direct influence of the tariffs themselves, then because of the Chinese government’s likely reaction. Analysts worry that the Chinese will retaliate by slapping duties on U.S. polysilicon. Also at risk is the U.S. solar installation business, which has thrived during this period of low-cost panels.

This is one of the critical defects of the AD/CVD regime. It focuses like a laser on assisting industries seeking protection from competition while systematically—indeed statutorily—ignoring the adverse impacts of that “assistance” on downstream U.S. industries. (Bastiat points out that people tend to err by focusing on what is immediately seen, while failing to consider the ripple effects of actions that are less readily observed; U.S. trade remedy law demands that we commit that error!)

Much more often than not (80% of AD measures in the last decade), the foreign product subject to duties is an intermediate good required by downstream U.S. industries. And these downstream firms—the overwhelming victims of AD/CVD duties—have no legal standing in the proceedings that lead to the imposition of duties that raise their costs of production and drive them offshore or out of business. Under the statutes, the U.S. International Trade Commission is forbidden from considering the likely impact on downstream firms. In this age of globalized production and transnational supply chains, nothing could be more absurd.

About the so-called non-market economy methodology used to calculate margins of dumping and, ultimately, duty rates in Chinese (and Vietnamese) antidumping cases, the editorial asks:

But how much should a Chinese-made solar panel cost? The answer isn’t obvious. Commerce’s estimating methods—using Thailand’s economy as a surrogate for China’s—don’t inspire confidence.

These Cato papers (here and here) provide the dirty details of the capriciousness inherent in NME antidumping methodology. This brand new Cato analysis from Scott Lincicome, which documents—among other things—the global green energy subsidies race, explains how the U.S. countervailing duty law does not redress foreign subsidization, but rather punishes U.S. consuming industries and end-users. Getting tough on China means America’s wealth and jobs creators take it on the chin.

In closing, the editorial states:

And if the Chinese want to subsidize U.S. solar-panel buyers for the time being, there’s a good case to let them.

This is just another example of the administration’s policies working at cross purposes. To the fanfare of the Sierra Club and other environmental groups, President Obama has rhetorically championed the idea of greening our energy consumption profile. Of course, one of the biggest obstacles to that goal has been that the costs don’t justify the benefits. Hasn’t Chinese dumping and subsidization helped to reduce that obstacle? And aren’t duties on Chinese solar panels anathema to that goal?

Duties on solar panels, wind towers, and presidential interventions to block foreign investments in U.S. wind farms suggest that industrial policy—and not environmental policy—explains the president’s interest in green energy.

Recognizing in an editorial that duties imposed to benefit one industry or one firm (as is often the case with trade remedies measures) cause collateral damage to other industries is a laudable development for the Washington Post.  We look forward to the follow-up editorial calling for explicit repeal of the self-flagellating U.S. antidumping law.

Is the Long-Awaited Snowfall Increase in Antarctica Now Underway?

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”

Whenever the topic of rising seas comes up, we point out that Antarctica is expected to gain mass through enhanced snowfall in a warmer climate, and therefore its contribution to global sea level rise should be negative—that is, the water locked up in the added snowfall there will act to reduce the level of the globe’s seas. The models used by the Intergovernmental  Panel on Climate Change (IPCC) in their 2007 Fourth Assessment Report project the sea level reduction from this mechanism by the end of the 21st century to amount to somewhere between 2 cm and 14 cm (roughly 1 to 6 inches). While this is not a lot, the main point is that Antarctica is not expected to be a contributor to rising seas as the climate warms. Without a large contribution from Antarctica, we will not approach alarmist projections of a meter-plus of sea level rise by century’s end.

Up to now, though, Antarctica has not exactly been with the program.

Instead of gaining mass through increased snowfall, there have been indications that Antarctica is losing ice (contributing to sea level rise) as ice discharge from its coastal glaciers exceeds gains from snow increases (which have been hard to find).  One has to wonder whether Antarctica, contrary to expectations, will continue to lose mass and become an important contributor sea level rise, or whether the projected increases in snowfall have just not yet reached a magnitude sufficient to offset the loss from glacial discharge.

Things are starting to change down there.

The research that has gotten the most attention on the subject of Antarctic mass balance has been based on observations made by the Gravity Recovery And Climate Experiment (GRACE) satellite.  This orbiter senses changes in gravity (i.e., mass) which can be caused by increasing snow and ice loads over the continent.  One key piece of information which must be factored into the calculations of ice mass change is the change in the underlying geologic formations, which are still rebounding from enormous amounts of ice lost after the end of the last ice age.  This geologic motion, known as the glacial isostatic adjustment (GIA), is largely modeled rather than directly observed. Our level of knowledge (or lack thereof) of the true GIA adds a sizable amount of uncertainty to GRACE-based estimates of the ice mass changes over time in Antarctica (and Greenland, the northern hemisphere’s cheap imitation of Antarctica).

In a widely cited finding, Velicogna (2009) reported that Antarctica was losing ice at a rate of about 104 gigatons per year (Gt/yr) during the period 2002–2006, increasing to a loss rate of 246 Gt/yr during 2006–2009 (about 374 Gt of ice are equivalent to 1 mm of sea level).  Rignot et al. (2011) also found an acceleration of ice loss there, increasing from a loss of about 209 Gt/yr (in 2003-2007) to about 265 Gt/yr from 2007 to 2010.  However, Wu et al. (2010) argued that the GIA model used in these previous studies is incorrect, and that when a more accurate GIA model is incorporated in the GRACE-based ice mass change calculations, Antarctica was only losing about 87 Gt/yr during the period 2002–2008.

Support for the GRACE-based calculations comes from the general agreement between the GRACE numbers and those calculated from studies of changes in the grounding lines of coastal glaciers and the ice flow across those grounding lines in association with the other aspects of the mass balance.  This method is known as the Input-minus-Output Method (IOM).  The IOM estimates of the average ice loss from Antarctica over the past several decades (1992–2007) lie somewhere around 136 Gt/yr, in rough agreement with the GRACE-based estimates.  However, the IOM is also subject to a lot of uncertainty. An attempt by Zwally and Giovinetto (2011) to reduce the uncertainty and increase the accuracy resulted in an IOM-based estimate of a loss of only 13 Gt/yr over the same 18-yr period and led the researchers to conclude that:

Although recent reports of large and increasing rates of mass loss with time from GRACE-based studies cite agreement with IOM results, our evaluation does not support that conclusion.

It seems that as the calculations and derivations are improved, the amount of ice mass that Antarctica is supposedly losing gets less and less.

Or perhaps it isn’t losing any mass.

Using a set of observations from a series of satellites that have been in orbit since 1992 and that measure changes in the height of the surface of the ice (ICESat), NASA’s Jay Zwally and colleagues (2012) report that Antarctica is gaining mass. Zwally recently presented his findings to a workshop of the Ice-Sheet Mass Balance and Sea Level expert group of the Scientific Committee on Antarctic Research and the International Arctic Science Committee. According to his abstract, Zwally reported that “During 2003 to 2008, the mass gain of the Antarctic ice sheet from snow accumulation exceeded the mass loss from ice discharge by 49 Gt/yr (2.5% of input), as derived from ICESat laser measurements of elevation change.”

Zwally further added, “A slow increase in snowfall with climate warming, consistent with model predictions, may be offsetting increased dynamic losses.”

So the “global warming, leading to increased snowfall, leading to a drawdown of global sea level” mechanism may be operating after all.

A paper to soon appear in Geophysical Research Letters give us another enticing look at recent snowfall changes in Antarctica.  In “Snowfall driven mass change on the East Antarctic ice sheet,” Carmen Boening and colleagues from NASA’s Jet Propulsion Laboratory report that extreme precipitation (snowfall) events in recent years (beginning in 2009) have led to a dramatic gain in the ice mass in the coastal portions of East Antarctica amounting to about 350 Gt in total (Figure 1).

Figure 1. Timeseries of snow accumulation in coastal East Antarctica (shaded region in inset).
(Source: Boening et al., 2012)
Boening et al. reported that the increase in ice mass in East Antarctica has not completely offset the loss of ice mass during the same time in West Antarctica, but as this comparison is made using GRACE data, it is hard to know just how accurate it is.

Also note that a few years with a lot of snowfall does not mean that a change in the long-term snowfall rate has occurred.  Nevertheless, the situation bears careful watching.

Putting everything together, we conclude that many of the claims that Antarctica is rapidly losing ice and increasingly contributing to a rise in global sea levels must now be, at the very least, tempered, if not overturned entirely. Time will certainly tell. And time will also tell just how much we need to worry about future sea level rise. Currently, the answer seems to be “not overly much.”


References:

Boening, C. et al., 2012. Snowfall-drive mass change on the East Antarctic ice sheet. Geophysical Research Letters, in press, DOI:10.1029/2012GL053316.

Rignot, E., et al., 2011. Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise. Geophysical Research Letters, L05503, DOI:10.1029/2011GL046583

Velicogna, I., 2009. Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE. Geophysical Research Letters, 36, L19503, DOI: 10.1029/2009GL040222.

Wu, X., et al., 2010. Simultaneous estimation of global present-day water transport and glacial isostatic adjustment. Nature Geoscience, 3, DOI: 10.1038/NGEO938.

Zwally, H.J., and M.B. Giovinetto, 2011. Overview and assessment of Antarctic ice-sheet mass balance estimates: 1992-2009. Surveys in Geophysics, 32, 351-376, DOI: 10.1007/s10712-011-9123-5.

Zwally, H.J., et al., 2012. Mass gains of the Antarctic ice sheet exceed losses. Presentation to the SCAR ISMAA Workshop, July 14, 2012, Portland Oregon.